1. Field of the Invention
The present invention relates generally to providing stable fluorescent additives for use in an ink composition, which may be used in ink detection or security applications.
2. Description of the Related Art
Identifying and detecting specific ink compositions used in an image forming device may allow for the image forming device to optimize print quality based on the ink identified. In addition, identifying and detecting specific ink compositions may help in solving printhead warranty issues. To identify the ink, the ink may include a fluorescent additive. The fluorescent additive in the inks may be detected by emitting a UV light, from an LED or other light source, and detecting light emitted from the ink using a phototransistor. Inks may be identified by the amount of light emitted by the inks, by the wavelength(s) at which the ink emits light as well as other characteristics of the emitted light.
Fluorescent additives, however, may often loose their ability to provide fluorescence over time, or upon exposure to an environmental condition (e.g. heat). This may be the result of decomposition and/or alteration of the chemical structure of the fluorescent additive, thereby compromising its ability to absorb light and fluoresce. It may also be due to a shift in the additives' ability to fluoresce at a particular excitation wavelength or range of wavelengths. That being the case, it would be useful to develop a stable ink formulation that offers fluorescence over the course of its anticipated shelf life for a given printing application.